1. Field of the Invention
This invention relates to a multi-type air conditioner system with a starting control for parallel operated compressors and, more particularly, to an air conditioner system constituted by a heat pump type refrigeration cycle including an outdoor unit having at least two variable-capacity compressors, and a plurality of indoor units.
2. Description of the Related Art
Generally, in such a multi-type air conditioner system as described above, a single operation using one compressor or a parallel operation using two compressors is performed in accordance with a required capacity of each indoor unit.
In such an air conditioner system, when the single operation using one compressor is switched to the parallel operation using two compressors, the starting load of the second operated compressor is influenced by the delivery pressure of the first operated compressor and is increased. As a result, a starting error may be caused in the second compressor.
In addition, while the second compressor is stopped or its start operating frequency is shifted to a command frequency, the pressure in its case becomes higher than that in the compressor case of the first compressor. For this reason, an effect of equally supplying a refrigeration oil from the first compressor to the second compressor is lost, so that the second compressor may be undesirably locked due to burning caused by a shortage of oil.